Seawater Concentration Water Resource System

Abstract

The present invention relates to a process system for the resource recovery of seawater concentrate, and more specifically, to a process system capable of recovering useful resources from seawater concentrate while simultaneously providing desalinated water at a level suitable for discharge into seawater.

Description

Technology Field

[0001] The present invention relates to a process system for the resource recovery of seawater concentrate, and more specifically, to a process system capable of recovering useful resources from seawater concentrate while simultaneously providing desalinated water at a level suitable for discharge into seawater. Background Technology

[0002] As water shortages become a serious global issue, the scale of seawater desalination is steadily increasing every year, and it is expected to reach approximately 2 million tons per day by 2030.

[0003] However, the highly concentrated brine (about 7%) generated during the seawater desalination process is discharged into the ocean and is known to cause destruction of marine ecosystems. Accordingly, local governments in regions where seawater desalination is active, such as the Middle East, the western United States, and Australia, are implementing regulations on the discharge of brine.

[0004] Zero Liquid Discharge (ZLD) technology, which extracts as much fresh water as possible from concentrated brine to leave only solid waste, has garnered attention as a solution to the problem of concentrated brine discharge; however, it is not recognized as a realistic solution due to its low economic feasibility. The reason for this low economic feasibility is that the value of the product is low compared to the high energy consumption of the process. This high energy consumption is due not only to the thermal energy required to raise the temperature of the water—which accounts for most of the total weight of the concentrated brine—but also to the energy required for the phase change of the water. The low value of the product is attributed to the fact that the product consists entirely of approximately 930 kg of fresh water per ton of concentrated brine, and the solid salt contains impurities, resulting in a lack of industrial value. Prior art literature

[0005] Republic of Korea Registered Patent Publication No. 10-2395019 The problem to be solved

[0006] The objective of the present invention is to recover useful resources from seawater concentrate through an integrated process that combines electrodialysis, chemical treatment, ion exchange, evaporative concentration, and electrolysis technologies. means of solving the problem

[0007] To achieve the above objective, a seawater concentrate resource recovery process system according to one embodiment of the present invention comprises: a purification unit for obtaining NaCl purified water from seawater concentrate; a concentration unit for obtaining concentrated treated water from the NaCl purified water; and a resource recovery unit for recovering useful resources from the concentrated treated water.

[0008] The above purification unit may include one or more of an electrodialysis device, a chemical treatment device, an ion exchange device, and a nanofilter device.

[0009] The above purification unit may be such that the seawater concentrate is sequentially treated in an electrodialysis device; a chemical treatment device; and an ion exchange device.

[0010] The above purification unit may further include a nanofilter device disposed upstream of the electrodialysis device.

[0011] The above concentration unit may include one or more of an evaporative concentration device and a reverse osmosis device.

[0012] The above resource recovery unit may include an electrolysis device. Effects of the invention

[0013] The present invention has the effect of minimizing marine pollution during ocean discharge by providing desalinated water that can be released into the seawater during the seawater desalination process, while simultaneously obtaining useful resources from seawater concentrate. Brief explanation of the drawing

[0014] Figure 1 illustrates a configuration diagram of a seawater concentrate resource recovery process system according to one embodiment of the present invention. FIGS. 2A and 2B illustrate the configuration of a purification section of a seawater concentrate resource recovery process system according to one embodiment of the present invention. FIGS. 3a and 3b illustrate the configuration of an electrodialysis device in the purification section of a seawater concentrate resource recovery process system according to one embodiment of the present invention. Figure 4 shows a photographic image of the electrode after operation depending on whether the pH of the electrode solution of the electrodialysis device in the purification section of the seawater concentrate resource utilization system according to one embodiment of the present invention is adjusted. FIG. 5 illustrates a configuration diagram of a chemical treatment device in the purification section of a seawater concentrate resource recovery process system according to one embodiment of the present invention. FIG. 6 illustrates a configuration diagram of an ion exchange device in the purification section of a seawater concentrate resource recovery process system according to one embodiment of the present invention. FIGS. 7a and 7b illustrate the configuration of a concentration unit in a seawater concentrate resource recovery process system according to one embodiment of the present invention. FIG. 8 illustrates the configuration of the purification section and the concentration section of a seawater concentrate resource utilization process system according to one embodiment of the present invention. FIGS. 9A and 9B illustrate the configuration of a resource recovery unit in a seawater concentrate resource recovery process system according to one embodiment of the present invention. FIG. 10 illustrates a configuration diagram of an electrolysis device in the resource recovery unit of a seawater concentrate resource recovery process system according to one embodiment of the present invention. FIGS. 11a to 11d illustrate exemplary diagrams of a seawater concentrate resource recovery process system according to one embodiment of the present invention. Specific details for implementing the invention

[0015] Hereinafter, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0017] Referring to FIG. 1, a seawater concentrate resource utilization process system (1) according to one embodiment of the present invention includes a purification unit (10); a concentration unit (20); and a resource utilization unit (30).

[0018] The seawater concentrate resource recovery process system (1) can obtain resources such as hydrogen (H2), chlorine (Cl2), and sodium hydroxide (NaOH) by removing many ions from the seawater concentrate separated from the seawater desalination process, thereby discharging seawater treated water at a level that can be discharged into seawater.

[0020] The purification unit (10) contains Mg in the seawater concentrate. 2+ , Ca 2+ , SO4 2- The accumulated NaCl purified water may be discharged by removing divalent ions such as the above, and the purification unit (10) may be composed of one or more devices for removing ions as a purification means. Accordingly, referring to FIGS. 2a and 2b, it may include one or more of an electrodialysis device (11); a precipitation treatment device (12); an ion exchange device (13); and a nanofilter device (14), and if two or more devices are included, the arrangement order of any two or more of the electrodialysis device (11); a chemical treatment device (12); an ion exchange device (13); and a nanofilter device (14) may be changed according to the process to remove ions from the seawater concentrate.

[0022] Referring to FIG. 3a, the electrodialysis device (11) purifies NaCl in concentrated water and includes an electrodialysis cell (111); a desalination tank (112); an electrode solution tank (113); and a concentration tank (114).

[0023] More specifically, referring to FIG. 3b, the electrodialysis cell (111) includes an anode (1111); a cathode (1112); and an electrolytic section (1113). The anode (1111) and the cathode (1112) are spaced apart to face each other, and the electrolytic section (1113) is positioned between the anode (1111) and the cathode (1112).

[0024] The electrolytic section (1113) includes an electrolyte (11131); a cation exchange membrane (11132); and an anion exchange membrane (11133), wherein the cation exchange membrane (11132) and the anion exchange membrane (11133) are disposed between the anode section (1111) and the cathode section (1112), and a plurality of cation exchange membranes (11132) and anion exchange membranes (11133) may be disposed alternately. As an example, a first cation exchange membrane (11132a), a first anion exchange membrane (11133a), a second cation exchange membrane (11132b), a second anion exchange membrane (11133b), a third cation exchange membrane (11132c), and a third anion exchange membrane (11133c) may be alternately arranged between the anode (1111) and the cathode (1112).

[0025] In the electrolytic section (1113), a concentration chamber (11134) is formed by a cation exchange membrane (11132) and an anion exchange membrane (11133). For example, a first concentration chamber (11134a) is formed between the first cation exchange membrane (11132a) and the first anion exchange membrane (11133a), a second concentration chamber (11134b) is formed between the second cation exchange membrane (11132b) and the second anion exchange membrane (11133b), and a third concentration chamber (11134c) is formed between the third cation exchange membrane (11132c) and the third anion exchange membrane (11133c). In the first to third concentration chambers (11134a to 11134c), the concentration of NaCl is... through ion exchange between the cation exchange membrane (11132) and the anion exchange membrane (11133). It may be that purified water with elevated NaCl is located there.

[0026] In the electrolytic section (1113), a demineralization chamber (11135) is formed by a cation exchange membrane (11132) and an anion exchange membrane (11133). For example, a first demineralization chamber (11135a) is formed between the first anion exchange membrane (11133a) and the second cation exchange membrane (11132b), and a second demineralization chamber (11135b) is formed between the second anion exchange membrane (11133b) and the third cation exchange membrane (11132c). The first demineralization chamber (11135a) and the second demineralization chamber (11135b) may contain demineralized water in which the concentration of NaCl is lowered by ion exchange between the cation exchange membrane (11132) and the anion exchange membrane (11133).

[0027] The desalination tank (112) receives concentrated seawater, and the received concentrated water flows into an electrodialysis cell (111). The desalinated water, from which ions have been removed in the electrodialysis cell (111), may be recirculated back into the desalination tank (112). Accordingly, the desalination tank (112) may be arranged to be connected to an electrolysis unit (1113) to supply concentrated seawater, and may be arranged to be connected to a desalination chamber (11135) to allow the desalinated water to be recirculated. If the concentration of the desalinated water recirculated into the desalination tank (112) is higher than the concentration of seawater, it is supplied back to the electrolysis unit (113); if the concentration is at the same level as the concentration of seawater recirculated into the desalination tank (112), the desalinated water may be discharged as seawater.

[0028] The concentration tank (113) collects concentrated water in which ions (Na+, Cl-) have accumulated through the electrodialysis cell (111), and collects NaCl purified water through the electrodialysis cell (111). The NaCl purified water collected in the concentration tank (113) may be transferred to the next process (e.g., the concentration unit (20)), or may be transferred to the chemical treatment device (12) or the ion exchange device (13) within the purification unit (10).

[0029] The electrode solution tank (114) stores an electrode solution that comes into direct contact with the electrode (anode part (111); and cathode part (112)), and may supply the electrode solution to the anode part (111); and cathode part (112). The electrode solution stored in the electrode solution tank (114) may contain an acidic substance, and as an example, the electrode solution stored in the electrode solution tank (114) may contain sulfuric acid (H2SO4), and the pH of the electrode solution may be 4 or lower. Through this, the pH of the desalination tank (112); and the concentration tank (113) can be maintained at 6 or lower. Also, the anode part (111); It is possible to prevent the formation of scale on the electrodes (anode and cathode) within the cathode section (112), and to prevent crumbling or the formation of pinholes on the ion exchange membranes (cation exchange membrane and anion exchange membrane) in contact with the electrode section (anode section (111); and cathode (112)), thereby enabling the sustainable operation of the electrodialysis device (11). As an example, referring to FIG. 4, when the pH of the electrode solution is not controlled to 4 or lower, it can be seen in FIG. 4 (a) that scale is formed and pinholes (inset) are formed on the electrode (cathode) of the cathode section (1112), but when the pH of the electrode solution is not controlled to 4 or lower, it can be seen in FIG. 4 (b) that scale is not formed on the electrode (cathode) of the cathode section (1112).

[0031] Referring to FIG. 5, the purification unit (10) may include a chemical treatment device (12), and the chemical treatment device (12) may generate a precipitate through chemical treatment of seawater concentrate or NaCl purified water (NaCl purified water treated in the electrodialysis device (11)), and may remove divalent ions through the generated precipitate. The divalent ions removed by the chemical treatment device (12) are Mg 2+ or Ca 2+ It may be, and the form of the precipitate may be a hydrate or a carbonate, and as an example, it may be Mg(OH)2, Ca(OH)2, CaCO3 or MgCO3.

[0032] The chemical treatment device (12) may include a first chemical treatment device (121) and a second chemical treatment device (122), and the seawater concentrate or NaCl purified water flowing into the chemical treatment device (12) may be primarily treated in the first chemical treatment device (121), and the primary chemically treated water treated in the first chemical treatment device (121) may be introduced into the second chemical treatment device (122) and treated secondarily.

[0033] The first chemical treatment device (121) may precipitate divalent ions in the form of hydrates by adding sodium hydroxide (NaOH) to seawater concentrate, and as an example, the precipitate may be Mg(OH)2 or Ca(OH)2.

[0034] The second chemical treatment device (122) may precipitate secondary ions in the form of carbonates by introducing carbon dioxide (CO2) into the seawater concentrate or the treated water discharged from the first chemical treatment device (121), and as an example, the precipitate may be CaCO3 or MgCO3.

[0036] Referring to FIG. 6, the ion exchange device (13) is a seawater concentrate or NaCl purified water (NaCl purified water treated in an electrodialysis device (11) or a chemical treatment device (12)) of Mg 2+ Concentration and Ca 2+ For reducing the concentration, the ion exchange device (13) may be an ion exchange resin, and Mg which is a divalent ion 2+ and Ca 2+ cast Mg of seawater concentrate or NaCl purified water selectively through ion exchange 2+ Concentration and Ca 2+ It may be a method to reduce the concentration. The NaCl purified water flowing into the ion exchange device (13) may be treated in an electrodialysis device (11) and / or a chemical treatment device (12).

[0037] The ion exchange device (13) may be a chelate ion exchange resin (CLR-08), and the ion exchange device (13) may have 1M HCl or 1M NaOH circulating therein, and more specifically, 1M HCl within the ion exchange device (13) circulates first so that the saturated Mg within the ion exchange device (13) 2+ and Ca 2+ ul H + By replacing it with, the ion adsorption capacity can be regenerated. Subsequently, 1M NaOH is circulated within the ion exchange device (13) and H within the ion exchange device (13) + 를 Na + By replacing it with Na + , Mg 2+ and Ca 2+ When purified water with NaCl, which is a mixed solution, passes through an ion exchange resin, Mg 2+ and Ca 2+ It can selectively adsorb [it]. Meanwhile, the ion exchange device (13) may be washed with deionized water (DI water) to remove residual HCl or residual NaOH resulting from the circulation of 1M HCl or 1M NaOH.

[0039] Referring to FIG. 2b, the nanofiltration (NF) device (14) may remove divalent ions in the concentrated water, and more specifically, the divalent ions are Mg 2+ , Ca 2+ or SO4 2- It may be. For example, it may be placed at the very front end of the process in the overall configuration of the purification unit (10), and more specifically, by being placed at the front end of the electrodialysis device (11), the concentrated water discharged through the nanofilter device (14) may be injected into the electrodialysis device (11).

[0041] The concentration unit (20) produces concentrated treated water with an improved concentration of NaCl by concentrating the NaCl purified water treated in the purification unit (10), and the produced concentrated treated water may be a crystalline slurry, and the concentrated treated water may have a concentration of at least 26% of NaCl.

[0042] Referring to FIGS. 7a and 7b, the concentration unit (20) may be either an evaporative concentration device (21) or a reverse osmosis device (22).

[0043] Referring to FIG. 7a, the evaporation concentration device (21) may be any one of a Multi-Effect Distillation (MED) device, a Multi-Stage Flash (MSF) device, and a Mechanical Vapor Compression (MVC) device.

[0044] Referring to FIG. 8, the distilled water generated in the evaporation concentration device (21) may be mixed with NaCl purified water, and preferably may be mixed with NaCl purified water discharged to the electrodialysis device (11).

[0046] Referring to FIG. 7b, the reverse osmosis (RO) device (22) may separate distilled water from NaCl purified water discharged to the purification unit (10) by reverse osmosis and transfer the crystalline slurry to the resource recovery unit (30). The distilled water separated from the reverse osmosis (RO) device (22) may be drinking water.

[0048] The resource recovery unit (30) may obtain useful resources from the concentrated treated water received from the concentration unit (20).

[0049] Referring to FIGS. 9a and 9b, the resource recovery unit (30) may include an electrolysis device (31); a concentrated treated water storage tank (32); a chlorine removal device (33); and a heater (34), and the resource recovery unit (30) may further include a resource recovery chemical treatment device (35); and a resource recovery ion exchange device (36).

[0050] The electrolysis device (31) is for collecting useful resources from the crystalline slurry discharged from the concentration unit (20), and the useful resources may be hydrogen (H2) and chlorine (Cl2).

[0051] Referring to FIG. 10, the electrolysis device is composed of an anode chamber (311); a cathode chamber (312); and an ion exchange membrane (313), wherein the anode chamber (311) includes an anode (3111) and the cathode chamber (312) includes a cathode (3121).

[0052] The electrolysis device (31) may be a chlor-alkali device, wherein concentrated treated water discharged from the concentration unit (20) is injected into the anode chamber (311) and chlorine (Cl2) is generated at the anode (3111), and sodium hydroxide (NaOH) at a low concentration is injected into the cathode chamber (312) and hydrogen (H2) is generated at the cathode (3121).

[0053] After chlorine (Cl2) is generated in the anode chamber (311), the concentrated treated water (hereinafter referred to as 'electrolytic treated water') that has been electrolyzed may be discharged from the electrolysis device (31), pass through the chlorine removal device (33) and the heater (34), and flow into the concentrated treated water storage tank (32).

[0054] The cathode chamber (312) is supplied with low concentration NaOH (32% NaOH), and after the electrolysis reaction, high concentration NaOH (> 32% NaOH) and hydrogen (H2) are discharged from the cathode chamber (312).

[0055] The concentrated treated water storage tank (32) may receive the concentrated treated water discharged from the concentration unit (20) and supply it to the anode chamber of the electrolysis device (31) or the resource recovery chemical treatment device (35). As an example, referring to FIG. 9a, when the NaCl concentration of the concentrated treated water in the concentrated treated water storage tank (32) is 30% or less (< 30% NaCl), the concentrated treated water may be supplied to the anode chamber of the electrolysis device (10). Meanwhile, referring to FIG. 9b, when the NaCl concentration of the concentrated treated water in the concentrated treated water storage tank (32) is greater than 30% (> 30% NaCl), the concentrated treated water may be supplied to the resource recovery chemical treatment device (35).

[0056] The electrolytic treated water discharged from the anode chamber (311) of the electrolysis device (31) may be fed into a chlorine removal device (33) to remove residual chlorine (Cl2) in the electrolytic treated water, and then fed into a heater (34) to recirculate the electrolytic treated water having a concentration of 23% NaCl into a concentrated treated water storage tank (32). The electrolytic treated water recirculated into the concentrated treated water storage tank (32) may be supplied back to the anode chamber (311) of the electrolysis device (31) together with the concentrated treated water.

[0057] Referring to FIG. 9b, the resource recovery unit (30) may further include a resource recovery chemical treatment device (35) and a resource recovery ion exchange device (36). The resource recovery chemical treatment device (35) and the resource recovery ion exchange device (36) may be included when the NaCl concentration of the concentrated treated water in the concentrated treated water storage tank (32) is greater than 30% (> 30% NaCl).

[0058] The resource recovery chemical treatment device (35) may generate a precipitate through chemical treatment of the concentrated treated water received from the concentration unit (20), and may remove divalent ions through the generated precipitate. The divalent ions removed by the resource recovery chemical treatment device (35) are Mg 2+ or Ca 2+It may be, and the form of the precipitate may be a hydrate or a carbonate, and as an example, it may be Mg(OH)2, Ca(OH)2, CaCO3 or MgCO3.

[0059] The resource recovery chemical treatment device (35) may precipitate divalent ions in the form of hydrates and carbonates by introducing sodium hydroxide (NaOH) and carbon dioxide (CO2), and as an example, the precipitate may be Mg(OH)2, Ca(OH)2, CaCO3 or MgCO3.

[0060] The resource recovery ion exchange device (36) is positioned downstream of the resource recovery chemical treatment device (35), and the resource recovery ion exchange device (36) may be an ion exchange resin, and Mg which is a divalent ion 2+ and Ca 2+ cast Mg in concentrated treated water through selective ion exchange 2+ Concentration and Ca 2+ The concentration may be reduced, and the concentrated treated water ion-exchanged through the resource ion exchange device (36) may be supplied to the anode chamber (311) of the electrolysis device (31).

[0061] In addition, the resource ion exchange device (36) may have the same configuration as the ion exchange device (13) of the purification unit (10).

[0063] For example, referring to FIG. 11a, a seawater concentrate resource utilization process system (1) according to one embodiment of the present invention may include a purification unit (10); a concentration unit (20); and a resource unit (30). The purification unit (10) may include a nanofilter device (14); an electrodialysis device (11); a chemical treatment device (12); and an ion exchange device (13) along the seawater concentrate inflow path. The concentration unit (20) may include an evaporation concentration device (21). The resource utilization unit (30) may include a concentrated treated water storage tank (32); an electrodialysis device (31); a chlorine removal device (33); and a heater (34). By placing the nanofilter device (14) at the very front end of the purification unit (10), divalent ions can be removed in advance, thereby reducing the burden of the purification process placed at the rear end.

[0065] As another example, referring to FIG. 11b, a seawater concentrate resource recovery process system (1) according to one embodiment of the present invention includes a purification unit (10); a concentration unit (20); and a resource unit (30). The purification unit (10) includes a chemical treatment device (12) and an electrodialysis device (11) along the seawater concentrate inflow path. The concentration unit (20) includes an evaporation concentration device (21). The resource recovery unit (30) may include a concentrated treatment water storage tank (32); a resource recovery chemical treatment device (35); a resource recovery ion exchange device (36); an electrodialysis device (31); a chlorine removal device (33); and a heater (34). By placing the chemical treatment device (12) at the very front of the purification unit (10), the yield of value-added precipitates can be increased and the carbon dioxide capture effect can be maximized.

[0067] As another example, referring to FIG. 11c, a seawater concentrate resource recovery process system (1) according to one embodiment of the present invention includes a purification unit (10); a concentration unit (20); and a resource unit (30). The purification unit (10) includes a chemical treatment device (12) along the seawater concentrate inflow path, the concentration unit (20) includes an evaporation concentration device (21), and the resource recovery unit (30) may include a concentrated treatment water storage tank (32); a resource recovery chemical treatment device (35); a resource recovery ion exchange device (36); an electrodialysis device (31); a chlorine removal device (33); and a heater (34). By placing the chemical treatment device (12) at the very front of the purification unit (10), the yield of value-added precipitates can be increased and the carbon dioxide capture effect can be maximized.

[0069] As another example, referring to FIG. 11d, a seawater concentrate resource recovery process system (1) according to one embodiment of the present invention includes a purification unit (10); a concentration unit (20); and a resource unit (30). The purification unit (10) includes a chemical treatment device (12) along the seawater concentrate inflow path, the concentration unit (20) includes a reverse osmosis device (22), and the resource recovery unit (30) may include a concentrated treated water storage tank (32); a resource recovery chemical treatment device (35); a resource recovery ion exchange device (36); an electrodialysis device (31); a chlorine removal device (33); and a heater (34). By placing the chemical treatment device (12) at the very front of the purification unit (10), the yield of value-added precipitates can be increased, the carbon dioxide capture effect can be maximized, and energy consumption can be minimized by replacing the energy-intensive evaporation concentration and electrodialysis processes with a reverse osmosis process.

[0071] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention. Explanation of the symbols

[0072] 1: Seawater Concentrate Resource Recovery Process System 10: Refining Department 20: Concentration Department 30: Resource Recycling Department

Claims

Claim 1 A seawater concentrate resource recovery process system comprising: a purification unit for obtaining NaCl purified water from seawater concentrate; a concentration unit for obtaining concentrated treated water from the NaCl purified water; and a resource recovery unit for recovering useful resources from the concentrated treated water. Claim 2 A seawater concentrate resource utilization process system according to claim 1, wherein the purification unit comprises one or more of an electrodialysis device, a chemical treatment device, an ion exchange device, and a nanofilter device. Claim 3 A seawater concentrate resource utilization process system according to claim 1, wherein the purification unit is such that the seawater concentrate is sequentially treated in an electrodialysis device; a chemical treatment device; and an ion exchange device. Claim 4 A seawater concentrate resource utilization process system, wherein, in paragraph 3, the purification unit further comprises a nanofilter device disposed upstream of the electrodialysis device. Claim 5 A seawater concentrate resource utilization process system according to claim 1, wherein the concentration unit comprises one or more of an evaporative concentration device and a reverse osmosis device. Claim 6 A seawater concentrate resource recovery process system according to claim 1, wherein the resource recovery unit includes an electrolysis device.

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